Barcodes are ubiquitous in our daily lives. Virtually every mobile phone can read various types of barcodes. Examples of barcodes include DataMatrix codes, PDF417 codes, Quick Response (QR) codes, Aztec codes, Maxi codes, and the like. Barcodes may be used for any number of purposes, from product identification and authentication, to the creation of coupons, to the addressing of poetry on the World Wide Web.
A barcode may be scanned and read by a wide variety of devices, including but not limited to cellular telephones, digital cameras, smartphones, personal digital assistants, tablet devices, electronic readers, personal computers and portable satellite navigation devices. The generation of various barcodes may be governed by established international standards, such as ISO/IEC 18004:2006 covering quick response (QR) codes, and any successor or replacement standard.
Barcodes have been used in several secure document applications, such as the generation and printing of tickets for admission to an event, or the creation of product packaging with barcodes that are used for supply chain tracking purposes. However, there are not sufficient protections in current barcodes that will prevent someone from making a copy that appears to be any different from the original barcode. Typically, the protections simply consist of written warnings against copying, which provide no technical safeguard against copying. Others print additional security patterns near the barcode, or superimpose holographic images on the barcode, each of which requires complex image capturing and processing techniques.
This document describes an augmented barcode, and a method of making it, that helps to guard against counterfeiting of documents that include the barcode.